The present invention relates to a synchronizing device for an electrically actuated coupling, by which aggregates or structural components of processing or finishing machines can be coupled to each other in a phase-angular position.
A synchronizing device can, for example, be used for an automatic and register-precise coupling of folding devices or transverse cutters of rotating printing machines. According to various operational conditions or various qualifications it is required that processing aggregates be register-precisely coupled to each other and uncoupled from each other. The meaning of the register-precise arrangement is that the edges of, for example the mirrors of the printing units in all the printing mechanisms should exactly superpose one another and the longitudinal and transverse folds and cutting lines should be carried out with high accuracy of fit.
It has been known in the art that the shafts to be coupled with each other should be brought in engagement in a predetermined angular position. Couplings utilized for this purpose have been operated by means of form-locking elements which were brought into engagement with each other in a predetermined position.
DE-AS No. 1,276,658 discloses an overload coupling for a folding apparatus, in which a bevel gear coupling is controlled by two commutator units in connection with running single revolution shafts and by respective sliding rings and brushes abutting the sliding rings. The commutator brushes close the electric circuit in their respective positions whereby an automatic coupling results. The disadvantage of this device resides in that the commutators and sliding brushes are subject to extensive wear and are also expensive in manufacture. Furthermore, the known device offers no possibilities to provide a coupling of the shafts in various angular positions. This is, however, desired in roller-rotary printing machines for registered adjustment of the units.
DE-OS No. 2,221,532, for example, discloses the device in which variable angular positions of the driving shaft and the driven shaft in office machines are possible. However, these various angular positions are possible only in rough steps. In this arrangement a controlled transmitter operates in connection with a multi-stage pawl coupling. The transmitter provides for a number of switch positions distributed over the circumference of the shaft. The pawls are controlled by light switches. The driving-side light barrier controls a timing putting into circuit, which driven-side light barrier controls a timing of switching-off of the pawls via a magnet. Due to the stationary arrangement of both light barriers on the machine frame the switching-on and switching-off points of the shafts relative to the frame are defined in connection with the timing discs. The timing switching-on of the shafts requires, however, a timing switching-off of these shafts. To uncouple the driven shaft from the driving shaft in any angular position and to couple these shafts with each other, upon a next rotation, in a selected angular position a fine sensitive correction of the angular position of the drifen shaft relative to the driving shaft has been required but has not been, however, possible in the known device. Furthermore, in the known device the coupling process has been performed intermittently and therefore all the structural elements of the device have been subject to wear and have generated significant noise in operation.